1. Field of the Invention:
The present invention relates to an epoxy resin composition wherein a polymer of a polyfluoroalkyl group-containing polymerizable compound, is dispersed in a particulate form.
2. Discussion of the Background:
Cured epoxy resins have excellent electrical properties, adhesion, chemical resistance and toughness, and they are widely used as coating materials, electrical insulating materials, lamination materials, structural materials or construction and building materials. However, commonly employed cured products of epoxy resins inherently have OH groups and high polarity, whereby the moisture absorptivity and water absorptivity are high. Therefore, their properties are not necessarily satisfactory for application to coatings where moisture is unwanted or for application to electrical insulating materials. In order to overcome such drawbacks, it has been attempted to apply various fluorine-type compounds to the surface of the cured products, but no adequate moisture resistance and water resistance have not been obtained.
With the foregoing technical background, the present inventors have conducted various studies to develop an epoxy resin composition having excellent moisture and water resistance.
As a method for improving the moisture and water resistance of a cured product of an epoxy resin, an attempt has been made to blend a fluorinated oligomer to an epoxy resin. For example, Japanese Unexamined Patent Publication No. 40161/1985 discloses a method wherein a polyfluoroalkyl group-containing acrylate or methacrylate oligomer is blended to various resins to improve the moisture resistance. However, in this method, the polyfluoroalkyl group-containing oligomer is added to a resin for blending, whereby dispersion of the oligomer in the resin is not necessarily adequately uniform, and there will be non-uniformity in the moisture and water resistance. Thus, such a method can hardly be regarded as being satisfactory.